While the technical and performance considerations of an observatory’s azimuth rotation system (ORS) are fundamentally distinct from those of a telescope’s azimuth rotation system (TRS), their impact on the capital cost, maintenance cost, and overall telescope uptime and reliability metrics can be equally impactful. Furthermore, due to its inherently larger scale, higher loads, extreme stiffnesses, and exposure to a larger variety of environmental forces, the design and construction of an ORS poses unique technical challenges that merit an appropriately unique approach. In particular, construction imperfections can have an unexpectedly outsized impact on ORS mechanisms loads, leading to underestimated design loads and premature component failures. In response, this study proposes a methodology of analysis, design, and construction of an ORS that is fundamentally distinct from that of a typical TRS. The need for extremely tight tolerances and high precision is deemphasized, in exchange for a more rigorous analytical approach that ensures that all performance and reliability objectives can be achieved while following tolerance schemes more typical of the commercial built environment. To do so, the proposed methodology derives mechanism and structural loads by pairing typical building codes with a Monte Carlo analysis; the presented techniques can be used to derive loads for various general arrangements of ORS mechanisms, including a variety of restraint schemes, structural and mechanism compliances, and tolerance envelopes. Representative simulation results generated with SAP2000 are presented along with general design guidelines for detailing an observatory rotation system with economical tolerances, reduced maintenance demands, and high long-term reliability.
The Canada France Hawaii Telescope Corporation (CFHT) plans to repurpose its observatory on the summit of Maunakea and operate a new wide field spectroscopic survey telescope, the Maunakea Spectroscopic Explorer (MSE). MSE will upgrade the observatory with a larger 11.25m aperture telescope and equip it with dedicated instrumentation to capitalize on the site, which has some of the best seeing in the northern hemisphere, and offer its user’s community the ability to do transformative science. The knowledge and experience of the current CFHT staff will contribute greatly to the engineering of this new facility.
MSE will reuse the same building and telescope pier as CFHT. However, it will be necessary to upgrade the support pier to accommodate a bigger telescope and replace the current dome since a wider slit opening of 12.5 meters in diameter is needed. Once the project is completed the new facility will be almost indistinguishable on the outside from the current CFHT observatory. MSE will build upon CFHT’s pioneering work in remote operations, with no staff at the observatory during the night, and use modern technologies to reduce daytime maintenance work.
This paper describes the design approach for redeveloping the CFHT facility for MSE including the infrastructure and equipment considerations required to support and facilitate nighttime observations. The building will be designed so existing equipment and infrastructure can be reused wherever possible while meeting new requirement demands. Past experience and lessons learned will be used to create a modern, optimized, and logical layout of the facility. The purpose of this paper is to provide information to readers involved in the MSE project or organizations involved with the redevelopment of an existing observatory facility for a new mission.
The Giant Magellan Telescope (GMT) is an Extremely Large Telescope (ELT) class observatory set to make history as one of the largest telescopes ever built. Vast improvements in the fields of optics, control systems, and mirror fabrication technologies have facilitated correspondingly drastic increases in the size and presence of ground-based telescopes previously thought to be impossible. Size for these observatories has increased to the point where conventional approaches impart seismic demands on the telescope structure and optics that are unmanageable. With this, a refined approach involving base isolation is being designed to provide seismic protection of a sensitive, invaluable instrument that will revolutionize our understanding of the universe.
The Giant Magellan Telescope (GMT), one of three next-generation extremely large telescopes (ELTs), will have a 25.4- meter diameter effective aperture, and will be located on the summit of Cerro Las Campanas in Chile. Developing a new observatory for cutting-edge science operations and a 50-year lifespan poses challenges that have resulted in competing design concepts. This paper discusses the concepts that have been adopted in the GMT site master plan, including designs for the site infrastructure, telescope enclosure, and facilities. The GMTO site has been in active construction since 2015, and in the past two years has completed important steps in site development including completion of residential and office facilities, road improvements, and other necessary infrastructure to support upcoming work. This paper concludes with an overview on managing design and construction simultaneously.
Telescope enclosure azimuth rotation systems have traditionally been supported by custom bogies with steel wheels and steel rails, with mixed results in terms of long-term reliability and performance. Because the enclosure azimuth rotation mechanisms are vital for the operational success of all telescopes, and because the scale of the Giant Magellan Telescope (GMT) enclosure will exceed that of all enclosures now in existence, the GMT project team has explored alternative solutions for enclosure rotation in search of cost, reliability, and maintainability benefits. Four concepts are studied: railway bogies, ring crane bogies, segmented slewing bearings, and THK curved linear bearings. All four concepts are highly developed systems engineered to meet specific design objectives and performance requirements, some objectives of which overlap those of the GMT enclosure azimuth rotation system; however, in all four instances, significant customization or development of an altogether new product would be required for fulfilment of the GMT performance requirements.
The Giant Magellan Telescope (GMT) will have a 25.4-meter diameter effective aperture, and is one the three currently planned next generation extremely large telescopes (ELTs). The GMT will be located at the summit of Cerro Campanas at the Las Campanas Observatory (LCO) in Chile, one the world’s best observing sites. This paper provides an overview of the site master plan comprising site infrastructure, enclosure, and facilities, and outlines the analysis of alternative trade studies that will lead to the final design. Also presented is an update of the site infrastructure development and preconstruction activities currently underway that will be completed prior to the beginning of enclosure construction near the end of 2016.
The Giant Magellan Telescope (GMT), one of several next generation Extremely Large Telescopes (ELTs), is a 25.4 meter diameter altitude over azimuth design set to be built at the summit of Cerro Campanas at the Las Campanas Observatory in Chile. This paper provides an update and overview of the ongoing efforts for the GMT site, infrastructure, facilities and enclosure design. The paper provides insight of the proposed systems, trade studies and approach resulting in the current design solution.
KEYWORDS: Data modeling, 3D modeling, Systems modeling, Computer aided design, Telescopes, Document management, Space telescopes, Observatories, Solid modeling, Process modeling
The Giant Magellan Telescope (GMT), one of several next generation Extremely Large Telescopes (ELTs), is a 25.4 meter diameter altitude over azimuth design set to be built at the summit of Cerro Campánas at the Las Campánas Observatory in Chile. The paper describes the use of Building Information Modeling (BIM) for the GMT project.
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